/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.calcite.sql.fun;

import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rel.type.RelDataTypeFactory;
import org.apache.calcite.sql.SqlAggFunction;
import org.apache.calcite.sql.SqlFunctionCategory;
import org.apache.calcite.sql.SqlKind;
import org.apache.calcite.sql.SqlSplittableAggFunction;
import org.apache.calcite.sql.type.OperandTypes;
import org.apache.calcite.sql.type.ReturnTypes;

import com.google.common.collect.ImmutableList;

import java.util.List;

/**
 * <code>Sum</code> is an aggregator which returns the sum of the values which
 * go into it. It has precisely one argument of numeric type (<code>int</code>,
 * <code>long</code>, <code>float</code>, <code>double</code>), and the result
 * is the same type.
 */
public class
SqlSumAggFunction extends SqlAggFunction {

    //~ Instance fields --------------------------------------------------------

    @Deprecated // to be removed before 2.0
    private final RelDataType type;

    //~ Constructors -----------------------------------------------------------

    public SqlSumAggFunction(RelDataType type) {
        super(
            "SUM",
            null,
            SqlKind.SUM,
            ReturnTypes.AGG_SUM,
            null,
            OperandTypes.NUMERIC,
            SqlFunctionCategory.NUMERIC,
            false,
            false);
        this.type = type;
  }

  //~ Methods ----------------------------------------------------------------

  @SuppressWarnings("deprecation")
  public List<RelDataType> getParameterTypes(RelDataTypeFactory typeFactory) {
    return ImmutableList.of(type);
  }

  @Deprecated // to be removed before 2.0
  public RelDataType getType() {
    return type;
  }

  @SuppressWarnings("deprecation")
  public RelDataType getReturnType(RelDataTypeFactory typeFactory) {
    return type;
  }

  @Override public <T> T unwrap(Class<T> clazz) {
    if (clazz == SqlSplittableAggFunction.class) {
      return clazz.cast(SqlSplittableAggFunction.SumSplitter.INSTANCE);
    }
    return super.unwrap(clazz);
  }
}

// End SqlSumAggFunction.java
